<!DOCTYPE html>
<html>
    <head>
        <title>租赁系统</title>
        <meta charset="UTF-8">
    </head>
    <body>
        <ul>
            <li onclick="document.querySelector('.iframe').src='home.php';">租赁首页</li>
            <li onclick="add()">添加租赁</li>
            
        </ul>
        <iframe class="iframe" src="home.php"></iframe>
    </body>
    <script>
        function add(){
            var add = document.querySelector(".iframe").src="add_rent.html";
        }
    </script>
    <style>
        .button_b{
            color: white;
            background-color: blue;
            border: none;
            border-radius: 5px;
        }
        body{
            display: flex;
        }
        iframe{
            border: none;
            width: 100%;
            height: 100vh;
        }
        ul{
            text-align: center;
            background-color: whitesmoke;
            height: 100vh;
            padding: 0;
            margin: 0;
            list-style: none;
            width: 100px;
        }
        li{
            background-color: white;
            border-bottom: 1px solid whitesmoke;
            width: 100px;
            height: 30px;
        }
        li:hover{
            background-color: whitesmoke;
        }
    </style>
</html>